Solar System Physics PhD Projects

The Physics department at Aberystwyth houses a diverse range of expertise amongst its staff members, alowing a large range of PhD projects available for study. The projects listed below are descriptions of possible projects along with the supervisors running them. For more information on each project, or information on developing your own project, contact an appropriate supervisor to discuss the posibilities in more details.

Solar Physics Projects

Time-normalized-optical-flow: a new tool for solar data analysis and to understand the nature and drivers of coronal propagating disturbances: Dr Huw Morgan.

A new image processing and optical flow method called Time-Normalized-Optical-Flow (TNOF) has been developed by the group. Applied to Extreme Ultraviolet (EUV) coronal images by the Atmospheric Imaging Assembly (AIA) instrument, it reveals continuous, faint coronal propagating disturbances (CPDs) across the whole corona (Morgan & Hutton; ApJ, V853, 145; 2018), and creates flow-maps that characterize and track these faint field-aligned motions. TNOF gives an exquisitely detailed tracing of the underlying coronal structure – far beyond the state of the art. This project has two connected aims: (i) To understand CPD activity and its impact on the corona through changes in emission/temperature distribution, and cooling/heating events. (ii) To develop the TNOF method to maturity and enabling its use as a powerful new tool in solar (and other) analysis. Development of TNOF is part of the UK software contribution to DKIST, has application to IRIS and the future Extreme Ultraviolet Imager/Solar Orbiter (EUI/SO), as well as to other instruments and other fields.

Field-aligned flows: a new observational constraint on the coronal magnetic field:Dr Huw Morgan.

A major challenge to solar and heliophysics is modeling the coronal magnetic field, which cannot be measured directly. The accuracy of such models is crucial to many aspects of coronal/heliospheric research (e.g. to link events at the Sun to interplanetary measurements). The aim of this project is, for the first time, to impose detailed, super-photospheric constraints on a magnetic model, gained from tracking faint field-aligned motions in the Extreme Ultraviolet (EUV) images of AIA/SDO (Morgan & Hutton; ApJ, V853, 145; 2018). This is a major advancement since current models lack quantitative observational constraints above the photosphere. The work is timely given the Extreme Ultraviolet Imager (EUI) and Polarimetric and Helioseismic Imager (PHI) onboard Solar Orbiter, and will be crucial to interpret data from missions including DKIST and Solar Probe.

The rapid acceleration of the solar wind is one of the big challenges in solar physics. Observations in coronal open-field regions show the presence of Alfven waves in the solar wind. Such waves are often invoked as the only candidates that can make the long trip from the visible surface of the Sun without being reflected.

The project will use analytical and numerical methods to investigate the direct coupling of the accelerating solar wind plasma with propagating Alfven waves in the linear and nonlinear regimes. The resulting transfer of energy and momentum from the waves and the effects on the plasma acceleration will be examined.

Lunar Projects

Crater count measurements of the lunar surface imply that the geology is generally of the order of thousands of million years old. However effects have been observed that suggest that there are, at least at local scales, minor changes. These are from impacts from order of kilogram mass meteorite impacts, active surface process relating to tectonic activity, potential outgassing, and electrostatic charging and subsequent levitation of dust particles. The proposed project will look for evidence of localized changes over the Moon’s entire surface of 38 million square kilometres by comparing automatically imagery of the same area, but separated in time, utilizing Lunar Reconnaissance (LRO) and earlier imagery. In order to reduce the search space, areas will be targeted for which the locality of impact flash events are known, where surface maturity maps suggest a freshly disturbed soil, steep slopes, young tectonic and meniscus hollow features. Patch-based correlation stereo matching and difference image techniques will be used to register images together in order to highlight changes. Candidates for this project would benefit from one or more of these areas of expertise: computer vision/programming, planetary geology, remote sensing, and GIS.

Short duration flashes, produced from meteoroid masses in the order of grams to several kilograms, striking the Moon, can be detected by video cameras attached to telescopes here on Earth, by studying the earthshine/night side of the Moon. This data tells us about current cratering rates on the Moon as well as the potential hazards to future astronauts and robotic surface missions. Apart from being able to estimate the size of impacting meteoroids, if they occur during a meteor shower of known velocity, blackbody temperatures maybe derived if videos are made through different filters. It is also suspected that higher resolution imaging may detect, occasionally, the spatial extent of ejecta cloud and/or illumination of nearby terrain from impacts. Calculations show that impacts flashes on the dayside of the Moon also stand a good chance of being observed, albeit with slightly lower sensitivity. The purpose of this project is to use a couple of remotely operated telescopes, and coordinate amateur astronomers across the world, to undertake video imaging of the night and day sides of the Moon in multiple wavebands, so as to improve our knowledge of impact flash light curves in time resolution, waveband, signal to noise ratio, and spatial resolution over existing observatories. You will have access to archive observation data, impact modelling software, and can even request LROC imagery to see if you can detect changes between prior and after impact high resolution images.

This is a technology demonstration project to highlight the uses and applications of close range remote sensing and monitoring of the sea surface. You will utilize a remotely operated telescope on the roof of the Physics building to monitor sea surface activity in terms of wave properties, sub-surface imaging, pollution and sediment characterization, object tracking for security, safety purposes, and wild life. Tidal height models will be used to specify the sea level surface, then dip angles and azimuth of parts of the image utilized to determine range and X,Y,Z position on the sea surface. In this way, any objects floating on the sea, viewed at shallow foreshortened views, can be used to calculate wave heights. Wide angle images taken with a colour camera, or filters, can yield information on sea colour and inform us about pollution or sediment load. Wide angle views and sweeps at high resolution, can be used to demonstrate monitoring and tracking of objects in the sea, for example swimmers swept out to sea, illegal fishing, and wild life.

Current PhD Projects

We have a number of current PhD students working within the Solar System Physics group. Some of their projects are listed below to give insight into the projects currently being investigated. Many of the current projects will tie-in with up and coming projects, allowing collaboration across the group.

Current Students

Thesis Title

Llyr Humphries

Constraints on coronal heating: A large study of TR/coronal rapid brightenings using IRIS and AIA data

James Pickering

Investigating the Coronal Heating Problem: Differential emission measure and time tag analysis of the corona in EUV